Fuel pump for internal combustion engines



y 1936- R. L ORANGE 2,041,422

7 FUEL PUMP FOR INTERNAL COMBUSTION-ENGINES Filed Aug. 6, 1.934

K 1 r l LP Patented May 19, 1936 UNITED STATES FUEL PUMP FOR INTERNALCOMBUSTION ENGINES Rudolf LOrange, Stuttgart-Feuerbach,

' Germany Application August 6, 1934, Serial No. 738,700

Germany August '7, 1933 1 Claim. (Cl. 103-37) This invention relates toa feedpump of the kind adapted to supply fuel at greaterthan'atmospheric pressure to the spray pump of an internalcombustionengine, and its object is to provide simple and eiiicient means formaintaining the supply of the feed pump equal to the fluctuating demandsput upon the spray pump.

This object is achieved according to the invention by arranging areciprocating pump plunger within a movable cylinder which is closed bya delivery valve and adapted to be displaced relative to the plunger, inopposition to a spring, by the pressure created by the plunger at thedelivery end of an enclosing casing, the cylinder being provided withsuction ports which are opened and closed by the plunger and which, on agiven displacement of the cylinder in opposition The accompanyingdrawing represents a yer-" tical section of a pump constructed accordingto the invention.

The illustrated pump comprises a cylinder B which forms a sliding fitwith an enclosing, upright casing A. The casing is provided with a fuelinlet K and with an outlet L, the latter being situated immediatelyabove amember H which closes the lower end of the casing andformsapressure chamber under the lower end of the cylinder. The communicationof the cylinder with the pressure chamber is controlled by the delivery'valve F which is supported by a spring G arranged between the valve andthe closing member H. The cylinder is provided with suction ports Jwhich are in constant communication .with the inlet K. A reciprocatingpump plungerC-is arranged within the cylinder B and acts by alternatelyopening and closing the suction ports J. The plunger has a head Nbetween which and a shoulder on the cylinder 9. spring D is arranged,which spring acts to produce'the suction stroke of the plunger and alsoto oppose move-- ment of the cylinder caused by fluid pressure at thepump outlet. The plunger bears against one end of an operating lever Mwhich is rocked by a cam 0 preferably mounted on the shaft of a spraypump to which fuel is supplied by the B. On the plunger 0 being lowered,the ports J are closed, and further movement of the plunger results infuel being forced beyond the delivery valve F into the pressure chamberand thence through the outlet L to the spray pump. As the action of thelatter varies according to the power output of the engine, the spraypump may be unable to take all the fuel delivered by the plunger C, inwhich case the pressure in the pressure chamber will increase and. causethe cylinder to be displaced in opposition to the spring D. At a givendisplacement. of the cylinder, in opposition to the spring D, theplunger will be ,unable to open the suction ports, and the stroke of theplunger will thus be rendered ineffective. As soon as the pressure isrelieved the pump will resume its action. Normally the forces will bebalanced so as to maintain the cylinder in a position which ensures thedelivery of the correct quantity of fuel to the spray pump.

. The arrangement has the particular advantage that the clearance spaceof the pump cylinder can be reduced to a minimum.

It is possible to arrange the cylinder and the casing in a horizontalposition, and also in a vertical position with the delivery vali'resituated at the top.

I claim:

A fuel pump for intemal-combustion engines, comprising a. cylindricalpump casing, a closing member for one end of said casing, the latterhaving axially spaced, lateral ports one situated near the closingmember and serving as an out- .let, the other port serving as an inlet,a pump cylinder arrangedin and forming a sliding fit with said casing,the cylinder having lateral suction ports communicating with the inletof the casing, stops on said closing member operative to keep thecylinder clear of the outlet of said casing, a spring-controlleddelivery valve supported on the closing member and bearing against theend of the cylinder, a reciprocating pump plunger in said cylinderadapted to act by alter-, nately opening and closing the suction ports,a head on said plunger, a cam operated lever arranged to bear againstsaid head for producing the pump stroke of the plunger, and a springarranged to bear at one end against the plunger head and at the otherend against the cylinder for producing the suction stroke, said springbeing operative to urge the cylinder into contact with the stops and toyield to allow the cylinder to be displaced by pressure at the outletuntil the suction ports can no longer be opened by the plunger.

' RUDOLF LORANGE.

